FVXX27 KNES 161600 VA ADVISORY DTG: 20170716/1600Z VAAC: WASHINGTON VOLCANO: USER MESSAGE PSN: XX AREA: XX RMK: THE 557TH WEATHER WING IS ISSUING THIS MESSAGE ON BEHALF OF THE WASHINGTON VAAC. 557 WW AND THE WASHINGTON VAAC ARE CONDUCTING A COORDINATED OPERATIONAL BACKUP TEST FROM 16/1600Z - 16/2100Z. PLEASE BE AWARE THAT 557 WW WILL ISSUE ANY NECESSARY VOLCANIC ASH ADVISORIES ON BEHALF OF THE WASHINGTON VAAC DURING THIS TIME FRAME. NNNN